Breast pumps are well known devices for extracting milk from a breast of a user. A breast pump may be used if the baby or infant is not itself able to extract milk from the breast, or if the mother is separated from the baby or infant and is to be fed with breast milk by someone else. Breast pumps typically comprise a rigid, funnel-shaped shield connected to a vacuum pump having a container for collecting the milk.
The shield of a breast pump is the interface between the user's breast and nipple with the pump and so its sizing is critical to maintaining the user's comfort whilst using the device. It is also important to ensure that the vacuum seal between the breast and the shield is maintained for optimal pumping. A problem with a conventional breast pump is that it has a shield of fixed size, so it can only cater for a limited range of breast and nipple sizes. However, if the shield is too small relative to the nipple, the nipple tends to fill the available space inside the shield and is likely to touch on the sides of the shield, resulting in chafing, friction and discomfort as negative pressure generated during use of the pump draws the nipple into the shield. On the contrary, if the shield is too large relative to the nipple, then there will be more dead space inside the shield which will reduce the efficiency of the pump system and limit the negative pressure achievable. It also introduces the possibility that the nipple will be pulled deeper into the pump and that the skin on areola or breast area surrounding the nipple will be subjected to chafing.
If the breast shield is not of the optimum size in relation to the size of the breast, there is a tendency for the user to apply greater pressure to the breast pump to urge the breast shield into closer contact with their breast. However, undue pressure on the breast can have a negative effect on the milk production and comfort for the mother. Excessive pressure may also cause the breast shield to block a milk duct resulting in further discomfort and inflammation of the breast tissue. Furthermore, as breast feeding is a delicate matter and is largely influenced by hormones, undue pressure on the breasts can have a negative impact on milk generation and lactation.
An ill-fitting breast shield can cause further problems for the user. Hormones, created by the body, trigger breast milk production and the creation of these hormones depends greatly on the comfort and confidence of the user. If the user perceives the breast shield to be uncomfortable, either visually or by feel, they may loose confidence and milk production may be impaired.
Research has shown that nipple diameter and length varies throughout the population and across different geographic regions and also that the size of the nipple can be different before, during and after expressing. Therefore, as fit is an important consideration when attempting to achieve maximum comfort for a user, a breast pump shield for a breast pump that is capable of accommodating a wide range of breast and nipple sizes is desirable. Furthermore, a breast will change shape and size during lactation. It would therefore be desirable to have the ability to adjust the breast shield during use, and without having to remove the shield from the breast, to ensure that the comfort and effectiveness does not deteriorate.
It is known to provide a breast pump body with a removable shield that may be replaced with another shield of a different size. However, removable shields are generally made from a hard plastic material and do not generally offer the user an enhanced level of comfort whilst using such a device. It is also necessary to store, and have readily accessible, the alternate breast shield, which is not always desirable or convenient. Changing a breast shield is also time consuming and means that the user has to remove their breast from the shield currently in use. As the shields are of finite sizes, they do not allow precise adjustment and it is necessary for a user to be satisfied with a breast shield which is closest in size or shape to that which is actually desired.
It is also known to provide a soft elastomer liner that may be disposed within a rigid shield of a breast pump and which is designed to adapt to the contour of the breast so as to provide comfort and a vacuum seal necessary for operating the pump. The resilience and compliance of such a liner helps to provide a vacuum and milk seal around the user's breast and also reduces friction on the breast and/or nipple when the negative pressure draws the breast and nipple in a direction into the pump. A cushion or insert may be formed from silicon or thermoplastic elastomer (TPE) which, in addition to providing an enhanced level of comfort, can also provide a warmer feeling to the breast.
Although a liner may improve the comfort for a user, a breast pump shield equipped with a liner still suffers from the problem that the liner will only accommodate a relatively small range of breast and/or nipple sizes resulting in a poor fit between the breast and/or the nipple with the insert for a relatively large number of breastfeeding women, causing discomfort and poor vacuum pressure generation.
The present invention seeks to overcome or substantially alleviate the aforementioned problems.